Individual components within systems in which high-speed data transfer occurs, such as computer networks and telecommunications systems, can be equipped with monitoring devices to audit the quality of the data transmissions. The monitoring devices typically count the number of errors that occur over a particular sampling interval and report the count at the end of the interval. The monitoring devices may also have the capability to activate an alarm when the number of errors exceeds a user-defined threshold. These alarms are called threshold crossing alarms. A monitoring device without the ability to activate a threshold crossing alarm can report the error count to a system that does have threshold crossing alarm capability.
Two general types of error events can be defined: dribble and burst. A dribble refers to a relatively low number of errors occurring over a relatively long period of time. A burst refers to a relatively large number of errors occurring over a relatively short period of time. Since some number of errors tends to occur even in a properly operating component, a dribble that occurs over a short period is not necessarily indicative of a problem. Similarly, a few random or low-level bursts do not necessarily indicate a problem. As a result, users of threshold crossing alarms may experience difficulty in setting the alarm threshold at a level that accurately indicates a legitimate problem in a component being monitored. If the alarm level is set high so that only significant bursts activate the alarm, a steady dribble of errors indicating an actual problem could go unnoticed. On the other hand, if the alarm level is set low so that dribbles activate the alarm, an excessive number of alarms could occur from non-significant bursts or increased dribbles. These false alarms may cause technicians monitoring the alarms to begin discounting or ignoring the alarms. As a result, when an alarm indicates an actual problem, the problem could again go unnoticed.